canvas-lms/lib/content_notices.rb

79 lines
2.7 KiB
Ruby

# frozen_string_literal: true
#
# Copyright (C) 2014 - present Instructure, Inc.
#
# This file is part of Canvas.
#
# Canvas is free software: you can redistribute it and/or modify it under
# the terms of the GNU Affero General Public License as published by the Free
# Software Foundation, version 3 of the License.
#
# Canvas is distributed in the hope that it will be useful, but WITHOUT ANY
# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
# A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
# details.
#
# You should have received a copy of the GNU Affero General Public License along
# with this program. If not, see <http://www.gnu.org/licenses/>.
#
module ContentNotices
NOTICE_ATTRIBUTES = [:tag, :text, :variant, :link_text, :link_target, :should_show]
class ContentNotice
attr_accessor *NOTICE_ATTRIBUTES
end
module ClassMethods
# opts must include:
# text: string (or Proc that returns string): text for the notice
# opts may optionally contain:
# variant: string: InstUI alert variant ('info', 'success', 'error', 'warning'; default is 'info')
# link_text: string (or Proc that returns string): text for a link that follows the notice
# link_target: string (or Proc that takes the context and returns a string): the target for said link
# should_show: Proc: callback that receives the context and user, and returns whether the notice should be displayed
# see course.rb for example usage
def define_content_notice(tag, opts)
notice = ContentNotice.new
NOTICE_ATTRIBUTES.each do |attr|
notice.instance_variable_set "@#{attr}", opts[attr] if opts.include?(attr)
end
notice.tag ||= tag
@content_notices ||= {}
@content_notices[tag] = notice
end
def content_notices
@content_notices
end
end
def self.included(base)
base.extend(ClassMethods)
end
def cn_cache_key(tag)
["content_notice_present", tag, self.asset_string].cache_key
end
# add a notice to this context. if the notice with the given tag is already active for the context,
# its expiration time will be reset.
def add_content_notice(tag, expires_in = nil)
Rails.cache.write(cn_cache_key(tag), true, expires_in: expires_in)
end
# remove a notice from this context
def remove_content_notice(tag)
Rails.cache.delete(cn_cache_key(tag))
end
# return an array of content notices that should be shown to the user
def content_notices(user)
self.class.content_notices.select do |tag, notice|
Rails.cache.read(cn_cache_key(tag)) && (notice.should_show.nil? || notice.should_show.call(self, user))
end.values
end
end